Automatic fire alarm system



April 13, 1948. 1'. J. TATE AU'IOIATIC FIRE ALARM SYSTEM Filod Fob. 21, 1947 ZON FIG.

FIG. 2

FIG.

IN V EN TOR.

1'1 J- TATE Patented Apr. 13, 1948' UNITED STATES PATENT OFFICE" Thomas J. Tate, Talladega, Ala. Application February 21, 1947, Serial No. 730,069

indicate or call attention to an abnormal condition, particularly a tire.

Numerous types of automatic fire alarm systems have, been proposed; however, these have not proven adequate toproperly warn, and consequently disastrous fires have taken a large toll of human life and property.

It is an object of the invention to provide an automatic fire alarm system of simple, inexpensive, constructioninvolving a small amount of material which can be easily installed, and which will adequately warn of the existence of a temperature above a predetermined amount.

Briefly stated, the invention comprises a circuit utilizing the telephone wires from a switchboard, which circuit is normally open, but is closed by means of a thermostat set to operate at a desired temperature as, forexample, at 135 F.,

and within the auxiliary circuit is a blinker element or other device of a. character which will produce intermittent interruption of the electrical energy to cause the flickering of a light or other signal on a switchboard.

Further objects and advantages-oi the invention will be apparent from the following description taken in conjunction with the drawings, wherein:

Fig. 1 is a diagrammatic view illustrating one I application of the invention;

Fig. 2, a similar view of a modified form; and

Fig. 3, a similar view employing a combination of the disclosures of Figs. 1 and 2.

With continued reference to the drawings, the invention may be applied to or used in conjunction with a conventional telephone system, including a switchboard or central station l0, generally referred to by the telephone company as a P. B, X system of forty-eight volts or less, lead wires or conductors H and I2 which terminate in a switchbox l3, from which telephone wires M are connected to an instrument consisting of a base I5 and a combination transmitter receiver It.

By picking up the receiver transmitter IS, a

1 Claim. (01. 179-5) a blinker element 20.

signal is actuated on the switchboard for attracting the switchboard operators attention. Any

number of lines of this character from the switchis permitted to move upwardly when the receiver is removed from its base, and this weight of the receiver is utilized to make and break an electrica circuit to the switchboard.

In order to provide automatic means for operating the same signal 011 a switchboard which ordinarily is a light, a mechanical drop or the like, auxiliary means is provided for completing a circuit to the switchboard through the conductors II and I 2.

One way of accomplishing this completion of the circuit is by means of a circuit loop consisting of a conductor l1, connected at one end to the conductor II, and having its other end connected to an adjustable thermostat l8 constructed to move at a fixed temperature as, for example, F., or to move upon a rapid rise in temperature, and engage a conductor 19 which includes The thermostat I8 is adapted to be located in any convenient position in the room to be guarded by the automatic alarm system, so that it will be influenced by heat in any part of the room. Thus, if a fire occurs, the thermostat upon reaching a temperature of 135 F., or other setting, closes a circuit through the blinker element to the switchboard actuating a signal or an alarm at the switchboard or central station, and due to the blinker element in the circuit the electrical impulses will be interrupted in a manner to cause intermittent operation of the signal, such as flickering of a light.

When installing fire alarm loops, two are preferably provided in each room to insure absolute operation should one become ineflective due to damage or the like.

It will, therefore, be readily understood that the automatic alarm system includes a central station and auxiliary stations, with a signal at the central station energized by completion of a circuit by a thermostat at the auxiliary station for operation of a signal at the central station. By this system each auxiliary station, which may be a room of a hotel, receives individual protection independent of every other station.

If desired, other conductors 2| and 22 may be substituted for the conductors H and i2 of the telephone system, and other central signal mechanism 23 may be used in addition to or in lieu of the switchboard Ill.

One important feature of the invention is that there is nothing to interfere with the telephone system when the invention is used, as there is only an open circuit connected to the conductors H and I2 until such time as the thermostat is energized to close the circuit.

,I v 3 v In Fig.2 the fire alarm system,'instead 01 being connected to the conductors H and I2, extend directly to the central station and may be connected to a signal mechanism 23 apart from the v switchboard"! and include a battery or other source of electrical energy 24 or may be connected directly to the switchboard l0 eliminating the necessity for the battery or source of electrical energy 24. v a

In Fig. 3, the'signalling systems of Figs. 1 and 2 "are combined and include thermostats l8 and 25, the thermostat l8 being adapted to operate a signal in the switchboard Ill and the thermostats l8 and 25 being adapted to operate signal mechanism 23 or it directly connected to the It will be obvious to those skilled in theart that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is shown in the drawing and described in the specification but only as indicated in the appended claim.

What is claimed is: An automatic fire alarm system which, in combination with an,--electrical telephone system having aoentral station with signalling means thereat and conductors extending to a telephone receiver at a location remote from said central station and through which conductors electrical energy is adapted to be supplied for actuating said signalling means at said central station from said switchboard, a signal in the switchboard or both.

receiver, consists of a blinker element, anormally open thermostatically operated switch constructed to close by rise in temperature, and

a circuit completing loop circuit connectedto said conductors and incorporating in series in said loop said blinker element and said thermostatically operated switch, said loop being energized upon the closing of said thermostat from said telephone system.

THOMAS J. TATE.

REFERENCES CITED 4 The following references are of record in the file of this patent: 

